1. Field of Invention
The present invention relates to jewelry chains and more specifically jewelry rope chains.
2. Discussion of Prior Art
One well known type of chain is a jewelry rope chain. Such chain is formed by interweaving links. The links can be of any shape including annular, square, triangular, or any other shape. The links can be formed of any shape wire such as round, square, triangular, or other shape. Additionally, the wire used may be hollow or solid material. Furthermore, hollow wire may include an interior seam or it may be seamless.
In standard rope chains, the links are formed with a gap in the exterior periphery. The links are assembled with the gap up and thereafter the next link is inserted with the gap down relative to the first link. This alternating arrangement of gap up and gap down is continued in a grouping fashion. Different ratios of the inner diameter of the links to the wire diameter may be used but conventional rope chains use a 3:1 ratio or larger (e.g., 5:1, 7:1, etc.). In a chain with a 3:1 ratio, the links are intertwined with two links fitting within the interior of a third link.
Typically, during manufacture of conventional rope chains, the links are temporarily held in place by two wires that are wound around the valleys of the double helix configuration formed by the links being interconnected. Thereafter, the links are soldered together in an alternating fashion. The wires are then removed and the links remain in place. The links provide a continuous interconnected chain which is flexible.
The above described typical arrangement is explained in more detail in U.S. Pat. No. 4,651,517 which is hereby incorporated herein by reference. Chains having a 3:1 ratio are described and additional odd ratios of 5:1, 7:1, 9:1, etc. are also described. In U.S. Pat. No. 4,934,135, which is hereby incorporated herein by reference, an arrangement using even ratios is described. Adjacent links are connected with their gaps oriented in the same direction and thereafter, additional links are inserted with their gaps oriented in the opposite direction. The number of links that fit within another link depends upon the ratio.
In U.S. Pat. No. 6,807,800, which is hereby incorporated herein by reference, a method is disclosed wherein links are arranged so that their gaps are not oriented in a continuously alternating pattern up and down. However, the links in the '800 patent are arranged so that some alternating of gap orientation is involved in the interweaving of the links to form the chain.
U.S. Pat. No. 6,311,470, which is hereby incorporated herein by reference, describes a reinforced rope chain. The disclosed rope chain is assembled from thin walled links in the classic manner (i.e., using an alternating gap orientations) and then reinforcing strands of precious metal are permanently attached (e.g., instead of the standard temporary metal wires). The precious metal strands remain in place even after the links are intertwined. The disclosed invention permits the utilization of thinner walled links and the intertwined precious metal strands provide strength and support to compensate for the thinner walled links.